Surgical stapling instrument having a single lockout mechanism for prevention of firing

ABSTRACT

A surgical instrument for laparoscopic and endoscopic clinical procedures simultaneously severs and staples tissue clamped in an end effector comprising an elongate channel, which holds a staple cartridge, and a pivotally attached anvil. An E-beam firing bar engages the channel and selectively engages the anvil during distal firing movements, wherein the tissue is severed and stapled driven upward from the staple cartridge to form against the anvil. In particular, a wedge integral to the staple cartridge is driven distally by a middle pin of the firing bar to effect stapling. A single lockout of the elongate channel responds to the presence of the wedge sled in its unfired position to allow the firing bar to fire. Otherwise, the single lockout prevents firing when the staple cartridge is missing or spent.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is continuation in part of U.S. patentapplication Ser. No. 10/441,424 filed on May 20, 2003; Entitled:Surgical Stapling Instrument Having a Single Lockout Mechanism forPrevention of Firing.

FIELD OF THE INVENTION

The present invention relates in general to surgical stapler instrumentsthat are capable of applying lines of staples to tissue while cuttingthe tissue between those staple lines and, more particularly, toimprovements relating to stapler instruments and improvements inprocesses for forming various components of such stapler instruments.

BACKGROUND OF THE INVENTION

Surgical staplers have been used in the prior art to simultaneously makea longitudinal incision in tissue and apply lines of staples on opposingsides of the incision. Such instruments commonly include a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

An example of a surgical stapler suitable for endoscopic applications isdescribed in U.S. Pat. No. 5,465,895, which advantageously providesdistinct closing and firing actions. Thereby, a clinician is able toclose the jaw members upon tissue to position the tissue prior tofiring. Once the clinician has determined that the jaw members areproperly gripping tissue, the clinician can then fire the surgicalstapler, thereby severing and stapling the tissue. The simultaneoussevering and stapling avoids complications that may arise whenperforming such actions sequentially with different surgical tools thatrespectively only sever or staple.

It is often advantageous to build an end effector for the surgicalstapler that is reusable. For instance, one patient may need a series ofsevering and stapling operations. Replacing an entire end effector foreach operation tends to be economically inefficient. This is especiallytrue if the end effector is built to be strong and reliable overrepeated operations. To that end, staple cartridges are fitted into theend effector prior to each operation of the surgical stapler. Thus, amuch smaller amount of the surgical staples is discarded after each use.

While the staple cartridge provides numerous advantages, it is desirableto prevent inadvertent firing of the surgical stapler when an unfiredstaple cartridge is not present. Otherwise, the severing of tissue mayoccur without the staples to minimize bleeding.

It is particularly desirable that preventing such inadvertent firing beaccomplished in a reliable way that is not subject to an interveningmalfunction. Moreover, for ease of manufacturing and assembly, it isfurther desirable that the lockout features be accomplished with aminimum number of components.

U.S. Pat. No. 5,129,570 by Schulze et al. discloses several lockoutdevices that prevent inadvertent firing when a cartridge is not present,and when the cartridge is spent or previously fired. Whereas the '570devices do indeed lockout the device, the solutions were complex andrequired a number of extra components.

Consequently, a significant need exists for an improved surgicalstapling and severing instrument that prevents inadvertent firing (i.e.,severing and stapling) when a staple cartridge is not installed or isspent, having been previously fired.

BRIEF SUMMARY OF THE INVENTION

The invention overcomes the above-noted and other deficiencies of theprior art by providing a single lockout mechanism that prevents firing asurgical stapling and severing instrument when either a staple cartridgeis not installed or is spent. In particular, the single lock mechanismprevents distal movement of a firing bar, and thus severing of tissue,in instances where simultaneous stapling would not occur.

In one aspect of the invention, a surgical stapling instrument includesa cartridge containing a plurality of staples and a wedge member. Thewedge member is moveable longitudinally within the cartridge to ejectthe staples from the cartridge. A firing member is provided that iscooperatively engagable with the wedge member and longitudinallymoveable to eject staples. A locking mechanism prevents distal movementof the firing bar after at least one of the staples has been ejected andthe firing bar has been moved proximally a predetermined distance. Thewedge member biases the firing member into an unlocked position prior tothe staples being deployed. The wedge and the firing bar are notcooperatively engaged when the instrument is in a locked position.

These and other objects and advantages of the present invention shall bemade apparent from the accompanying drawings and the descriptionthereof.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1. depicts a partially cut-away side elevation view of a surgicalstapling and severing instrument in an open position.

FIG. 2 depicts a cross-sectional side elevation detail view along theline 2—2 of FIG. 1 of an end effector of the surgical stapling andsevering instrument.

FIG. 3 depicts an enlarged side elevation view of the firing bar of thesurgical stapling and severing instrument of FIG. 2.

FIG. 4 depicts an enlarged front view of the firing bar of the surgicalstapling and severing instrument of FIG. 2.

FIG. 5 depicts a cross-sectional side elevation detail view of analternative end effector for the surgical stapling and severinginstrument of FIG. 1, incorporating a firing bar that lacks a middle pinfor preventing pinching of the end effector.

FIG. 6 depicts a side elevational view of a handle portion of a proximalend of the surgical stapling and severing instrument of FIG. 1 with aleft side removed to expose interior parts in an unclamped, unfired(“start”) position.

FIG. 7 depicts a perspective, exploded view of the handle portion of theproximal end of the surgical stapling and severing instrument of FIG. 1.

FIG. 8 depicts a side elevational view of the handle portion of theproximal end of the surgical stapling and severing instrument of FIG. 1with the left side removed to expose interior parts in the closed(“clamped”) position.

FIG. 9 depicts a side elevational view of the handle portion of proximalend of surgical stapling and severing instrument of FIG. 1 with the leftside removed to expose interior parts in the stapled and severed(“fired”) position.

FIG. 10 depicts an isometric view of the end effector at the distal endof the surgical stapling and severing instrument of FIG. 1 with theanvil in the up or open position exposing the staple cartridge andcutting edge of the firing bar.

FIG. 11 depicts an isometric, exploded view of the implement portion ofthe surgical stapling and severing instrument of FIG. 1.

FIG. 12 depicts an isometric view of the end effector at the distal endof the surgical stapling and severing instrument of FIG. 1 with theanvil in the up or open position with the cartridge largely removedexposing a single staple driver and a double staple driver as exemplaryand the wedge sled in its start position against a middle pin of thefiring bar.

FIG. 13 depicts an isometric view of the distal end of the surgicalstapling and severing instrument of FIG. 1 with the anvil in the up oropen position with the staple cartridge completely removed and a portionof an elongate channel removed to expose a lowermost pin of the firingbar.

FIG. 14 depicts a side elevation view in section showing a mechanicalrelationship between the anvil, elongate channel, and staple cartridgein the closed position of the surgical stapling and severing instrumentof FIG. 1, the section generally taken along lines 14—14 of FIG. 10 toexpose wedge sled, staple drivers and staples but also depicting thefiring bar along the longitudinal centerline.

FIG. 15 depicts a section view of the end effector of the surgicalstapling and severing instrument with the cartridge and firing bar inthe start position taken along line 15—15 of FIG. 10.

FIG. 16 depicts a section view taken along line 16—16 of FIG. 15 showingthe cross-sectional relationship between the firing bar, elongatechannel, wedge sled, staple drivers, staples and staple cartridge.

FIG. 17 depicts a side elevation section view of the surgical staplingand severing instrument of FIG. 1 taken along the longitudinalcenterline of the end effector in a partially closed but unclampedposition gripping tissue.

FIG. 18 depicts a partially cut-away side elevational view of thesurgical stapling and severing instrument of FIG. 1 in the closed orclamped position.

FIG. 19 depicts a side elevation view in centerline section of thedistal end of the surgical stapling and severing instrument of FIG. 1 inthe closed or clamped position with tissue properly compressed.

FIG. 20 depicts a partially cut-away side elevation view of the surgicalstapling and severing instrument of FIG. 1 in a partially firedposition.

FIG. 21 depicts a view in centerline section of the distal end of thesurgical stapling and severing instrument of FIG. 1 in a partially firedposition.

FIG. 22 depicts a partially cut-away side elevation view of the surgicalstapling and severing instrument of FIG. 1 in a fully fired position.

FIG. 23 depicts a view in centerline section of the distal end of thesurgical stapling and severing instrument of FIG. 1 in a fully firedposition.

FIG. 24 depicts a perspective view looking distally at the elongatechannel of FIG. 1 partially cut away to expose a cartridge body and asingle lockout mechanism engaging a middle pin of a firing bar.

FIGS. 25–28 depict a cross-sectional side detail view of the singlelockout mechanism, staple cartridge and firing bar of FIG. 24,sequentially shown in a cartridge loaded and unfired state in FIG. 25, acartridge being fired state in FIG. 26, a spent cartridge with firingbar being retracted state in FIG. 27, and spent cartridge with firingbar retracted state in FIG. 28.

FIG. 29 depicts the single lockout mechanism of FIG. 24 furtherincorporating a lockout trough.

FIG. 30 depicts a bottom perspective view of an elongate channel of FIG.1 partially cut away to show another single lockout mechanism engagingthe middle pin of a firing bar when a staple cartridge is missing.

FIGS. 31–34 depict a cross-sectional side detail view of the singlelockout mechanism of FIG. 30, sequentially shown in a cartridge loadedand unfired state in FIG. 31, a cartridge being fired state in FIG. 32,a spent cartridge with firing bar being retracted state in FIG. 33, anda spent cartridge with firing bar retracted state in FIG. 34.

FIG. 35 depicts a bottom perspective view of a proximal end of acartridge of FIG. 10 showing an alternate wedge sled having a notchtherein and an open cartridge tray having an open passageway therein.

FIGS. 36–39 depict a cross-sectional side detail view of an alternatelockout mechanism utilizing a lockout trough, staple cartridge andfiring bar, sequentially shown in a cartridge loaded and unfired statein FIG. 36, a cartridge being in a fully fired state in FIG. 37, a spentcartridge with firing bar being retracted state in FIG. 38, and thefiring bar locked out in FIG. 39.

DETAILED DESCRIPTION OF THE INVENTION

Turning to the Drawings, wherein like numerals denote like componentsthroughout the several views, FIG. 1 and 2 depict a surgical staplingand severing instrument 10 that is capable of practicing the uniquebenefits of the present invention. The surgical stapling and severinginstrument 10 incorporates an end effector 12 having an E-beam firingmechanism (“firing bar”) 14 that advantageously controls the spacing ofthe end effector 12. In particular, an elongate channel 16 and apivotally translatable anvil 18 are maintained at a spacing that assureseffective stapling and severing. Furthermore, firing (i.e., severing andstapling) is prevented from occurring if the instrument is not capableof stapling with a single lockout mechanism, which is described in moredetail below.

The surgical and stapling and severing instrument 10 includes a handleportion 20 connected to an implement portion 22, the latter furthercomprising a shaft 23 distally terminating in the end effector 12. Thehandle portion 20 includes a pistol grip 24 toward which a closuretrigger 26 is pivotally drawn by the clinician to cause clamping, orclosing, of the anvil 18 toward the elongate channel 16 of the endeffector 12. A firing trigger 28 is farther outboard of the closuretrigger 26 and is pivotally drawn by the clinician to cause the staplingand severing of clamped tissue in the end effector 12.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping a handle of an instrument.Thus, the end effector 12 is distal with respect to the more proximalhandle portion 20. It will be further appreciated that for convenienceand clarity, spatial terms such as “vertical” and “horizontal” are usedherein with respect to the drawings. However, surgical instruments areused in many orientations and positions, and these terms are notintended to be limiting and absolute.

Closure trigger 26 is actuated first. Once the clinician is satisfiedwith the positioning of the end effector 12, the clinician may draw backthe closure trigger 26 to its fully closed, locked position proximate tothe pistol grip 24.

Then, the firing trigger 28 is actuated. The firing trigger 28springedly returns when the clinician removes pressure. A release button30 when depressed on the proximal end of the handle portion 20 releasesany locked closure trigger 26.

A closure sleeve 32 encloses a frame 34, which in turn encloses a firingdrive member 36 that is positioned by the firing trigger 28. The frame34 connects the handle portion 20 to the end effector 12. With theclosure sleeve 32 withdrawn proximally by the closure trigger 26 asdepicted, the anvil 18 springedly opens, pivoting away from the elongatechannel 16 and translating proximally with the closure sleeve 32.

The elongate channel 16 receives a staple cartridge 37 that isresponsive to the firing bar 14 to drive staples into forming contactwith the anvil 18. It will appreciated that although a readilyreplaceable staple cartridge 37 is advantageously described herein, astaple cartridge 37 consistent with aspects of the present invention maybe permanently affixed or integral to the elongate channel 16, forinstance when a larger portion of the end effector 12 is replaced aftereach firing.

E-Beam Firing Mechanism

With particular reference to FIGS. 2–4, the firing bar 14 includes threevertically spaced pins that control the spacing of the end effector 12during firing. In particular, an upper pin 38 is staged to enter ananvil pocket 40 near the pivot between the anvil 18 and elongate channel16. When fired with the anvil 18 closed, the upper pin 38 advancesdistally within a longitudinal anvil slot 42 extending distally throughanvil 18. Any minor upward deflection in the anvil 18 is overcome by adownward force imparted by the upper pin 38.

Firing bar 14 also includes a lower most pin, or firing bar cap, 44 thatupwardly engages a channel slot 45 in the elongate channel 16, therebycooperating with the upper pin 38 to draw the anvil 18 and the elongatechannel 16 slightly closer together in the event of excess tissueclamped therebetween.

The firing bar 14 advantageously includes a middle pin 46 that passesthrough a firing drive slot 47 formed in a lower surface of thecartridge 37 and an upward surface of the elongate channel 16, therebydriving the staples therein as described below. The middle pin 46, bysliding against the elongate channel 16, advantageously resists anytendency for the end effector 12 to be pinched shut at its distal end.To illustrate an advantage of the middle pin 46, FIG. 5 depicts analternative end effector 12′ that lacks a middle pin on a firing bar14′. In this depiction, the end effector 12′ is allowed to pinch shut atits distal end, which tends to impair desired staple formation.

Returning to FIGS. 2–4, a distally presented cutting edge 48 between theupper and middle pins 38, 46 on the firing bar 14 traverses through aproximally presented, vertical slot 49 in the cartridge 37 to severclamped tissue. The affirmative positioning of the firing bar 14 withregard to the elongate channel 16 and anvil 18 assure that an effectivecut is performed.

Cambered Anvil with Selected Cartridge Gap

The affirmative vertical spacing provided by the E-Beam firing bar 14 issuitable for the limited size available for endoscopic devices.Moreover, the E-Beam firing bar 14 enables fabrication of an anvil 16with a camber imparting a vertical deflection at its distal end, similarto the position depicted in FIG. 5. This cambered anvil 16advantageously assists in achieving the desired gap in the end effector12 even with an anvil 16 reduced thickness, which is thus more suited tothe size limitations of an endoscopic device.

The E-Beam firing bar 14 further enables increased applications,especially in combination with a range of configurations of staplecartridges. For instance, a clinician may select a gray staple cartridgeyielding a 0.02 mm tissue gap, a white staple cartridge yielding a 0.04mm tissue gap, a blue cartridge yielding a 0.06 mm tissue gap, or agreen cartridge yielding a 0.10 mm tissue gap. The vertical height ofeach respective staple cartridge in combination with the length ofstaples and an integral wedge sled (described in more detail below)predetermines this desired tissue thickness with the anvil 18appropriately vertically spaced by the E-Beam firing bar 14.

Two-Axis Handle

With reference to FIGS. 6–9, the handle portion 20 is comprised of firstand second base sections 50 and 52, which are molded from a polymericmaterial such as a glass-filled polycarbonate. The first base section 50is provided with a plurality of cylindrical-shaped pins 54. The secondbase section 52 includes a plurality of extending members 56, eachhaving a hexagonal-shaped opening 58. The cylindrical-shaped pins 54 arereceived within the hexagonal-shaped openings 58 and are frictionallyheld therein for maintaining the first and second base sections 50 and52 in assembly.

A rotating knob 60 has a bore 62 extending completely through it forengaging and rotating the implement portion 22 about its longitudinalaxis. The rotating knob 60 includes an inwardly protruding boss 64extending along at least a portion of the bore 62. The protruding boss64 is received within a longitudinal slot 66 formed at a proximalportion of the closure sleeve 32 such that rotation of the rotating knob60 effects rotation of the closure sleeve 32. It will be appreciatedthat the boss 64 further extends through frame 34 and into contact witha portion of the firing drive member 36 to effect their rotation aswell. Thus, the end effector 12 (not shown in FIGS. 6–9) rotates withthe rotating knob 60.

A proximal end 68 of the frame 34 passes proximally through the rotatingknob 60 and is provided with a circumferential notch 70 that is engagedby opposing channel securement members 72 extending respectively fromthe base sections 50 and 52. Only the channel securement member 72 ofthe second base section 52 is shown. The channel securement members 72extending from the base sections 50, 52 serve to secure the frame 34 tothe handle portion 20 such that the frame 34 does not movelongitudinally relative to the handle portion 20.

The closure trigger 26 has a handle section 74, a gear segment section76, and an intermediate section 78. A bore 80 extends through theintermediate section 78. A cylindrical support member 82 extending fromthe second base section 52 passes through the bore 80 for pivotablymounting the closure trigger 26 on the handle portion 20. A secondcylindrical support member 83 extending from the second base section 52passes through a bore 81 of firing trigger 28 for pivotally mounting onthe handle portion 20. A hexagonal opening 84 is provided in thecylindrical support member 83 for receiving a securement pin (not shown)extending from the first base section 50.

A closure yoke 86 is housed within the handle portion 20 forreciprocating movement therein and serves to transfer motion from theclosure trigger 26 to the closure sleeve 32. Support members 88extending from the second base section 52 and securement member 72,which extends through a recess 89 in the yoke 86, support the yoke 86within the handle portion 20.

A proximal end 90 of the closure sleeve 32 is provided with a flange 92that is snap-fitted into a receiving recess 94 formed in a distal end 96of the yoke 86. A proximal end 98 of the yoke 86 has a gear rack 100that is engaged by the gear segment section 76 of the closure trigger26. When the closure trigger 26 is moved toward the pistol grip 24 ofthe handle portion 20, the yoke 86 and, hence, the closure sleeve 32move distally, compressing a spring 102 that biases the yoke 86proximally. Distal movement of the closure sleeve 32 effects pivotaltranslation movement of the anvil 18 distally and toward the elongatechannel 16 of the end effector 12 and proximal movement effects closing,as discussed below.

The closure trigger 26 is forward biased to an open position by a frontsurface 130 interacting with an engaging surface 128 of the firingtrigger 28. Clamp first hook 104 that pivots top to rear in the handleportion 20 about a pin 106 restrains movement of the firing trigger 28toward the pistol grip 24 until the closure trigger 26 is clamped to itsclosed position. Hook 104 restrains firing trigger 28 motion by engaginga lockout pin 107 in firing trigger 28. The hook 104 is also in contactwith the closure trigger 26. In particular, a forward projection 108 ofthe hook 104 engages a member 110 on the intermediate section 78 of theclosure trigger 26, the member 110 being outward of the bore 80 towardthe handle section 74. Hook 104 is biased toward contact with member 110of the closure trigger 26 and engagement with lockout pin 107 in firingtrigger 28 by a release spring 112. As the closure trigger 26 isdepressed, the hook 104 is moved top to rear, compressing the releasespring 112 that is captured between a rearward projection 114 on thehook 104 and a forward projection 116 on the release button 30.

As the yoke 86 moves distally in response to proximal movement of theclosure trigger 26, an upper latch arm 118 of the release button 30moves along an upper surface 120 on the yoke 86 until dropping into anupwardly presented recess 122 in a proximal, lower portion of the yoke86. The release spring 112 urges the release button 30 outward, whichpivots the upper latch arm 118 downwardly into engagement with theupwardly presented recess 122, thereby locking the closure trigger 26 ina tissue clamping position, such as depicted in FIG. 8.

The latch arm 118 can be moved out of the recess 122 to release theanvil 18 by pushing the release button 30 inward. Specifically, theupper latch arm 118 pivots upward about pin 123 of the second basesection 52. The yoke 86 is then permitted to move proximally in responseto return movement of the closure trigger 26.

A firing trigger return spring 124 is located within the handle portion20 with one end attached to pin 106 of the second base section 52 andthe other end attached to a pin 126 on the firing trigger 28. The firingreturn spring 124 applies a return force to the pin 126 for biasing thefiring trigger 28 in a direction away from the pistol grip 24 of thehandle portion 20. The closure trigger 26 is also biased away frompistol grip 24 by engaging surface 128 of firing trigger 28 biasingfront surface 130 of closure trigger 26.

As the closure trigger 26 is moved toward the pistol grip 24, its frontsurface 130 engages with the engaging surface 128 on the firing trigger28 causing the firing trigger 28 to move to its “firing” position. Whenin its firing position, the firing trigger 28 is located at an angle ofapproximately 45° to the pistol grip 24. After staple firing, the spring124 causes the firing trigger 28 to return to its initial position.During the return movement of the firing trigger 28, its engagingsurface 128 pushes against the front surface 130 of the closure trigger26 causing the closure trigger 26 to return to its initial position. Astop member 132 extends from the second base section 52 to prevent theclosure trigger 26 from rotating beyond its initial position.

The surgical stapling and severing instrument 10 additionally includes areciprocating section 134, a multiplier 136 and a drive member 138. Thereciprocating section 134 comprises a wedge sled in the implementportion 22 (not shown in FIG. 6–9) and a metal drive rod 140.

The drive member 138 includes first and second gear racks 141 and 142. Afirst notch 144 is provided on the drive member 138 intermediate thefirst and second gear racks 141, 142. During return movement of thefiring trigger 28, a tooth 146 on the firing trigger 28 engages with thefirst notch 144 for returning the drive member 138 to its initialposition after staple firing. A second notch 148 is located at aproximal end of the metal drive rod 140 for locking the metal drive rod140 to the upper latch arm 118 of the release button 30 in its unfiredposition.

The multiplier 136 comprises first and second integral pinion gears 150and 152. The first integral pinion gear 150 is engaged with a first gearrack 154 provided on the metal drive rod 140. The second integral piniongear 152 is engaged with the first gear rack 141 on the drive member138. The first integral pinion gear 150 has a first diameter and thesecond integral pinion gear 152 has a second diameter which is smallerthan the first diameter.

FIGS. 6, 8 and 9 depict respectively the handle portion 20 in the startposition (open and unfired), a clamped position (closed and unfired) anda fired position. The firing trigger 28 is provided with a gear segmentsection 156. The gear segment section 156 engages with the second gearrack 142 on the drive member 138 such that motion of the firing trigger28 causes the drive member 138 to move back and forth between a firstdrive position, shown in FIG. 8, and a second drive position, shown inFIG. 9. In order to prevent staple firing before tissue clamping hasoccurred, the upper latch arm 118 on the release button 30 is engagedwith the second notch 148 on the drive member 138 such that the metaldrive rod 140 is locked in its proximal-most position, as depicted inFIG. 6. When the upper latch arm 118 falls into the recess 122, theupper latch arm 118 disengages with the second notch 148 to permitdistal movement of the metal drive rod 140, as depicted in FIG. 9.

Because the first gear rack 141 on the drive member 138 and the gearrack 154 on the metal drive rod 140 are engaged with the multiplier 136,movement of the firing trigger 28 causes the metal drive rod 140 toreciprocate between a first reciprocating position, shown in FIG. 8, anda second reciprocating position, shown in FIG. 9. Since the diameter ofthe first pinion gear 150 is greater than the diameter of the secondpinion gear 152, the multiplier 136 moves the reciprocating section 134a greater distance than the drive member 138 is moved by the firingtrigger 28. The diameters of the first and second pinion gears 150 and152 may be changed to permit the length of the stroke of the firingtrigger 28 and the force required to move it to be varied.

It will be appreciated that the handle portion 20 is illustrative andthat other actuation mechanisms may be employed. For instance, theclosing and firing motions may be generated by automated means.

Separate and Distinct Closing and Firing End Effector

The end effector 12 of the surgical stapling and severing instrument 10is depicted in further detail in FIGS. 10–16. As described above, thehandle portion 20 produces separate and distinct closing and firingmotions that actuate the end effector 12. The end effector 12advantageously maintains the clinical flexibility of this separate anddistinct closing and firing (i.e., stapling and severing). In addition,the end effector 12 introduces the aforementioned ability toaffirmatively maintain the closed spacing during firing after theclinician positions and clamps the tissue. Both features procedurallyand structurally enhance the ability of the surgical stapling andsevering instrument 10 by ensuring adequate spacing for instances wherean otherwise inadequate amount of tissue is clamped and to enhance theclamping in instances where an otherwise excessive amount of tissue hasbeen clamped.

FIG. 10 depicts the end effector 12, which is in an open position by aretracted closure sleeve 32, with a staple cartridge 37 installed in theelongate channel 16. On a lower surface 200 of the anvil 18, a pluralityof stapling forming pockets 202 are arrayed to correspond to a pluralityof stapler apertures 204 in an upper surface 206 of the staple cartridge37. The firing bar 14 is at its proximal position, with the upper pin 38aligned in a noninterfering fashion with the anvil pocket 40. The anvilpocket 40 is shown as communicating with the longitudinal anvil slot 42in the anvil 18. The distally presented cutting edge 48 of the firingbar 14 is aligned with and proximally from removed from the verticalslot 49 in the staple cartridge 37, thereby allowing removal of a spentcartridge and insertion of an unfired cartridge, which is snapfit intothe elongate channel 16. Specifically, extension features 208, 210 ofthe staple cartridge 37 engage recesses 212, 214 (shown in FIG. 12) ofthe elongate channel 16.

FIG. 11 shows the implement portion 22 of the surgical stapling andsevering instrument 10 in disassembled form. The staple cartridge 37 isshown as being comprised of a cartridge body 216, a wedge sled 218,single and double drivers 220, staples 222, and a cartridge tray 224.When assembled, the cartridge tray 224 holds the wedge sled 218, singleand double drivers 220, and staples 222 inside the cartridge body 216.

Having a wedge sled 218 integral to the staple cartridge 37 enables anumber of flexible design options as compared to incorporating cammingsurfaces onto a firing bar itself. For instance, a number of differentstaple cartridges may be selected for use in the instrument 10 with eachstaple cartridge having a different configuration of rows of staples,each thus having a unique wedge sled configured to contact the middlepin 46 of the firing bar 14 while causing the driving of the staples222. As another example, the integral wedge sled 218 provides anopportunity for a number of lockout features, described in greaterdetail in the first and third aforementioned co-pending applications.

The elongate channel 16 has a proximally placed attachment cavity 226that receives a channel anchoring member 228 on the distal end of theframe 34 for attaching the end effector 12 to the handle portion 20. Theelongate channel 16 also has an anvil cam slot 230 that pivotallyreceives an anvil pivot 232 of the anvil 18. The closure sleeve 32 thatencompasses the frame 34 includes a distally presented tab 234 thatengages an anvil feature 236 proximate but distal to the anvil pivot 232on the anvil 18 to thereby effect opening and closing of the anvil 18.The firing drive member 36 is shown as being assembled from the firingbar 14 attached to a firing connector 238 by pins 240, which in turn isrotatingly and proximally attached to the metal drive rod 140. Thefiring bar 14 is guided at a distal end of the frame by a slotted guide239 inserted therein.

With particular reference to FIG. 12, a portion of the staple cartridge37 is removed to expose portions of the elongate channel 16, such asrecesses 212, 214 and to expose some components of the staple cartridge37 in their unfired position. In particular, the cartridge body 216(shown in FIG. 11) has been removed. The wedge sled 218 is shown at itsproximal, unfired position with a pusher block 242 contacting the middlepin 46 (not shown in FIG. 12) of the firing bar 14. The wedge sled 218is in longitudinal sliding contact upon the cartridge tray 224 andincludes wedges 228 that force upward the single and double drivers 220as the wedge sled 218 moves distally. Staples 222 (not shown in FIG. 12)resting upon the drivers 220 are thus also forced upward into contactwith the anvil forming pockets 202 on the anvil 18 to form closedstaples. Also depicted is the channel slot 45 in the elongate channel 16that is aligned with the vertical slot 49 in the staple cartridge 37.

FIG. 13 depicts the end effector 12 of FIG. 12 with all of the staplecartridge 37 removed to show the middle pin 46 of the firing bar 14 aswell as portion of the elongate channel 16 removed adjacent to thechannel slot 45 to expose the firing bar cap 44. In addition, portionsof the shaft 23 are removed to expose a proximal portion of the firingbar 14. Projecting downward from the anvil 18 near the pivot, a pair ofopposing tissue stops 244 prevent tissue being positioned too far upinto the end effector 12 during clamping.

FIG. 14 depicts the end effector 12 closed in a tissue clamping positionwith the firing bar 14 unfired. The upper pin 38 is in the anvil pocket40, vertically aligned with the anvil slot 42 for distal longitudinalmovement of the firing bar 14 during firing. The middle pin 46 ispositioned to push the wedge sled 218 distally so that wedge 228sequentially contacts and lifts double drivers 220 and the respectivestaples 222 into forming contact with staple forming pockets 202 in thelower surface 200 of the anvil 18.

FIG. 15 depicts the upper surface 206 of the staple cartridge 37 withthe firing bar 14 in its unfired, proximal position. The staplerapertures 204 are arrayed on each side of the vertical slot 49 in thestaple cartridge 37.

FIG. 16 depicts the end effector 12 near the pivot showing that theelongate channel 16 has opposing ramp portions 246 to thereby cooperatewith the tissue stops 244 of the anvil 18 (not shown in FIG. 16) toprevent tissue from jamming the end effector 12. Also depicted ingreater detail are the double drivers 220 and their relation to thestaples 222.

Operation

In use, the surgical stapling and severing instrument 10 is used asdepicted in FIGS. 1, 2, and 17–23. In FIGS. 1–2, the instrument 10 is inits start position, having had an unfired, fully loaded staple cartridge37 snap-fitted into the distal end of the elongate channel 16. Bothtriggers 26, 28 are forward and the end effector 12 is open, such aswould be typical after inserting the end effector 12 through a trocar orother opening into a body cavity. The instrument 10 is then manipulatedby the clinician such that tissue 248 to be stapled and severed ispositioned between the staple cartridge 37 and the anvil 18, as depictedin FIG. 17.

With reference to FIGS. 18–19, next, the clinician moves the closuretrigger 26 proximally until positioned directly adjacent to the pistolgrip 24, locking the handle portion 20 into the closed and clampedposition. The retracted firing bar 14 in the end effector 12 does notimpede the selective opening and closing of the end effector 12, butrather resides within the anvil pocket 40. With the anvil 18 closed andclamped, the E-beam firing bar 14 is aligned for firing through the endeffector 12. In particular, the upper pin 38 is aligned with the anvilslot 42 and the elongate channel 16 is affirmatively engaged about thechannel slot 45 by the middle pin 46 and the firing bar cap 44.

With reference to FIGS. 20–21, after tissue clamping has occurred, theclinician moves the firing trigger 28 proximally causing the firing bar14 to move distally into the end effector 12. In particular, the middlepin 46 enters the staple cartridge 37 through the firing drive slot 47to effect the firing of the staples 222 (not shown in FIGS. 20–21) viawedge sled 218 toward the anvil 18. The lower most pin, or firing barcap 44, cooperates with the middle pin 46 to slidingly position cuttingedge 48 of the firing bar 14 to sever tissue. The two pins 44, 46 alsoposition the upper pin 38 of the firing bar 14 within longitudinal anvilslot 42 of the anvil 18, affirmatively maintaining the spacing betweenthe anvil 18 and the elongate channel 16 throughout its distal firingmovement.

With reference to FIGS. 22–23, the clinician continues moving the firingtrigger 28 until brought proximal to the closure trigger 26 and pistolgrip 24. Thereby, all of the ends of the staples 222 are bent over as aresult of their engagement with the anvil 18. The firing bar cap 44 isarrested against a firing bar stop 250 projecting toward the distal endof the channel slot 45. The cutting edge 48 has traversed completelythrough the tissue. The process is complete by releasing the firingtrigger 28 and by then depressing the release button 30 whilesimultaneously squeezing the closure trigger 26 to open the end effector12.

Single Lockout for Missing/Spent Staple Cartridge

As described above, the E-beam firing bar 14 provides uniquecapabilities for affirmatively spacing the end effector 12 whilesimultaneously severing tissue and effecting the forming of staples oneach side of the cut. With reference to FIG. 24, preventing the distalmovement of the firing bar 14 thus prevents the inadvertent severing oftissue. A single lockout mechanism 270 advantageously responds to amissing staple cartridge 37 or a spent staple cartridge 37, the lattercondition depicted in FIG. 24, by blocking the middle pin 46 of thefiring bar (only the middle pin of the firing bar being shown in FIG.24).

In particular, the single lockout mechanism 270 is depicted as a pair ofbent spring fingers 272 positioned in the elongate channel 16 to respondto both conditions: missing cartridge and spent cartridge. Inparticular, the bent spring fingers 272 raise up to block the middle pin46 of the firing bar 14 when the wedge sled 218 (not shown in FIG. 24)is not present, such as when the cartridge 37 is removed or when thecartridge 37 has been fired.

FIGS. 25–28 depict the single lockout mechanism 270, specifically thebent sprint fingers 272 sequentially as the surgical stapling andsevering instrument 10 is fired. In FIG. 25, an unfired staple cartridge37 has been inserted into the elongate channel 16 with the wedge sled218 depressing the bent spring fingers 272 so that the firing drive slot47 formed between the cartridge 37 and the elongate channel 16 isunimpeded.

In FIG. 26, firing of the cartridge 37 has commenced, with the wedgesled 218 and the middle pin 46 of the firing bar 14 having distallytraversed off of the bent spring fingers 272, which then spring up intothe firing drive slot 47.

In FIG. 27, the staple cartridge 37 is now spent with the wedge sled 218fully driven distally and no longer depicted. The firing bar 14 is beingretracted proximally. Since the bent spring fingers 272 pivot from amore distal point, the firing bar 14 is able to ride up onto the bentspring fingers 272 during retraction, causing them to be depressed outof the firing drive slot 47.

In FIG. 28, the firing bar 14 is fully retracted and now confronts anon-depressed pair of bent spring fingers 272 to prevent distalmovement. The single lockout mechanism 270 thereby activated remainsduring the period in which the spent staple cartridge 37 is removeduntil an unfired staple cartridge 37 is installed.

FIG. 29 depicts a lockout trough 274 that may advantageously be includedin the single lockout mechanism 270 in order to provide increasedmechanical strength. In some applications, it may be desirable to resiststrong firing motions without damaging the bent spring fingers 272. Thelockout trough 274 communicates with the firing drive slot 47 when thebent spring fingers 272 are not depressed. Moreover, the lockout trough274 is downwardly ramped in a distal direction such that the middle pin46 of the firing bar 14 is directed toward an abutting surface 276 at adistal end of the lockout trough 274, thereby reacting the distalmovement of the firing bar 14 into an elongate channel 16′. Inparticular, the firing bar 14 in its initial position moves to a distaland lowered position, depicted at 14′, wherein the middle pin 46 movesto a position depicted as 46′. It will be appreciated that the upper pin38 and lower firing bar cap 44, as each moves to distal and loweredpositions 38′ and 44′ respectively, position the middle pin 46 againstelongate channel 16 so that the middle pin 46 enters the lockout trough274.

It will be further appreciated that the firing bar 14′ may be readilyretracted from the lockout trough 274. Moreover, insofar as the upperpin 38′ would be engaging the anvil 18 (not shown in FIG. 29) in thisposition, the clinician would have to retract the firing bar 14′ so thatthe anvil 18 could be opened in order to insert an unfired staplecartridge 37, and thus the firing bar 14 would be fully retracted andwould not impede the depressing of the bent spring fingers 272 to theirinactivated position.

FIG. 30 depicts another single lockout mechanism 270, depicted as a pairof lockout hooks 280 having ramped ends 282 distally placed with regardto attachment devices 284 inserted through apertures 286 in the elongatechannel 16. The ramped ends 282 lie above a hook recess 288 defined inthe elongate channel 16. Thus, when each ramped end 282 is contacted bya wedge sled 218 of an unfired staple cartridge 37 (not shown in FIG.30), the ramped ends 282 are depressed into the hook recess 288, therebyclearing the way for the middle pin 46 of the firing bar 14 (only themiddle pin shown in FIG. 30) to move distally to fire the staplecartridge 37. A thin shaft 290 coupling the attachment devices 284 torespectively to the ramped end 282 of each lockout hook 280 resilientlyresponds to absence of a wedge sled 218, as depicted, wherein the rampedends 282 return to impede the firing drive slot 47 to block a retractedmiddle pin 46 of the firing bar.

FIGS. 31–34 depict the sequence of operation of the lockout hooks 280.In FIG. 31, the staple cartridge 37 is unfired so that the distallypositioned wedge sled 218 depresses the ramped ends 282 into the hookrecess 288, allowing the middle pin 46 of the firing bar 14 to movedistally during firing, as depicted in FIG. 32. With the wedge sled 218and middle pin 46 distally removed with respect to the lockout mechanism270, the ramped ends 282 resiliently raise out of the hook recess 282 tooccupy the firing drive slot 47.

In FIG. 33, the firing bar 14 is being retracted to the point ofcontacting the ramped ends 282 of the lockout hook 280. Since the distalend of the ramped ends 282 is lower than the proximal part of the rampedends 282, the middle pin 46 of the firing bar 14 rides over the rampedends 282, forcing them down into the hook recess 288 until middle pin 46is past the ramped ends 282, as depicted in FIG. 34, wherein the rampedends 282 resiliently spring back up to block the middle pin 46. Thus,the firing bar 14 is prevented from distal movement while the spentstaple cartridge 37 is replaced with an unfired staple cartridge 37.

FIGS. 35–39 shows yet another alternate embodiment of a single lockoutmechanism 370 that utilizes a locking trough 274 within the elongatechannel 16. As shown in FIG. 35, the cartridge 37 is loaded with singleand double drivers 220 and staples 222 (not shown) and all areunmodified. An open cartridge tray 324 is attached to cartridge 372 anda coupling wedge sled 318 slidably mounted within. An open passageway317 is located at a distal end of the open cartridge tray 324 to providepassage of the middle pin 46 of the firing bar 14. A notch 319 can beseen located in a central nub 321 of the coupling wedge sled 318.

FIG. 36 is a side section view of the assembled end effector 12 of thesurgical stapling and severing instrument 10 in the unfired positionshowing the elements of the alternate embodiment of the lockoutmechanism 370.

For this alternate mechanism, a coupling firing bar 314 is used with asupport member or heel 323 in sliding contact with a floor 325 of theelongate channel 16. As shown, when firing bar 314 is fully retractedproximally, heel 323 is located proximally to a distal end of thechannel slot 45 that extends longitudinally along the bottom of elongatechannel 16. A spring bump 327 also extends upwards on coupling firingbar 314 to compress a leaf spring 329 and to exert a downward bias oncoupling firing bar 314. This downward bias ensures contact of the heel323 with the floor 325.

A coupling feature 331 extends distally from the coupling firing bar314. With an unfired cartridge installed, coupling feature 331 isadjacent to but not contacting the notch 319 within nub 321 of couplingwedge sled 318. When the instrument is fired, the coupling firing bar314 moves distally bringing coupling feature 331 into cooperativeengagement with the notch 319 of the coupling wedge sled 318 and beginsto push sled 318 distally. With additional distal movement of thecoupling firing bar 314, heel 323 slides off the floor 325 and isexposed to the open channel slot 45. The cooperative engagement of thecoupling feature 331 with the notch 319 prevents downward movement ofthe firing bar 14 (from the bias of leaf spring 327) during the firingstroke. Thus, during firing, firing bar 314 is held suspended over theopen channel slot 45 and open lockout trough 274 located within elongatechannel 16. As firing bar 314 moves distally during the firing stroke,spring bump 327 passes leaf spring 329 and reduces the downward biasfrom spring 329. FIG. 37 shows the coupling firing bar 314 at the end ofthe firing stroke with the coupling feature 331 in cooperativeengagement with notch 319 of the coupling wedge sled. If the firing bar314 is retracted at any point during the firing stroke, the couplingfeature 331 disengages with the coupling wedge sled 318 and sled 318remains stationary in the cartridge 37.

FIG. 38 shows the lockout mechanism 370 locked out. In this view, firingbar 314 retracted to the proximal most position after firing. As thefiring bar 314 retracts, the coupling feature 331 disengages from thestationary coupling wedge sled 318 and coupling firing bar 314 dropsunder spring bias until the middle pin 46 of firing bar 314 contacts andslides on an inner floor of the open cartridge tray 324. Firing bar 314continues to retract, bringing angled surface spring bump 327 back intocontact with the leaf spring 329 to increase the downward bias. Middlepin 46 continues to slide distally on the floor of open cartridge tray324 until the open passageway 317 (FIG. 35) of the open cartridge tray324 is reached and middle pin 46 drops through open passageway 317 andinto lockout trough 274. As the proximal movement of firing bar 314continues, the middle pin 46 slides up the angled proximal surface oflockout trough 274 and pin 46 begins sliding on floor 325 of theelongate channel 16. Continued proximal movement of firing bar 314brings an angled proximal surface of heel 323 into contact with aproximal end of channel slot 45 and lifts firing bar 314 up. Thisupwards motion lifts and disengages middle pin 46 from the floor 325 andfurther compresses leaf spring 329.

Should an attempt be made to fire the surgical stapling and severinginstrument 10 again, the lockout mechanism 370 will lock out as follows.Pulling on the firing trigger 28 a second time moves firing bar 314distally from the position of FIG. 38 and heel 273 slides off the floor325 and into the channel slot 45. Since the coupling wedge sled 318 isnot in the distalmost position, cooperative coupling cannot occurbetween the wedge sled 318 and firing bar 314 and leaf spring 329 biasesfiring bar 314 downwards until middle pin 46 of the firing bar 314 iscontacting and sliding on the floor 325. Since middle pin 46 extendslaterally in either side of firing bar 314, the pins contact the floor325 on either side of the channel slot 45. As shown in FIG. 39, furtherdistal movement of the coupling firing bar 314 drops middle pin 46 intolockout trough 274 where firing bar 14 is locked by contact of middlepin 46 with vertical abutting surface 276 of lockout trough 274 (FIG.29). In this locked position, leaf spring 329 applies a downward bias onfiring bar 314 to prevent the middle pin 46 from moving vertically andout of lockout trough 274 should the shaft be inverted. Release of thefiring trigger 28 will retract the firing bar 314 to the position ofFIG. 38. Any additional firing motions will move firing bar 314 back tothe locked position of FIG. 39 until a fresh cartridge 37 is installedwith a coupling wedge sled 318 in the distalmost position. Thus, when anunfired cartridge is used, the coupling wedge sled 318 acts as a bridgeto hold the firing bar 14 up above the channel slot 45 and lockouttrough 274 during the firing stroke. Once the coupling wedge sled 318moves distally passes the lockout trough 274 and the firing bar 314 isretracted, the instrument will lock out.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications mayreadily appear to those skilled in the art.

For example, a single lockout mechanism may comprise a spring-loadedplunger encompassed within the elongate channel 16 that moves upwardlyinto the firing drive slot 47 when not contacted by the wedge sled 218with the plunger presenting a hooked or otherwise

1. A surgical stapling instrument comprising: a cartridge containing aplurality of staples and a wedge member, said wedge member moveablelongitudinally within said cartridge to eject said staples fromcartridge; a firing bar cooperatively engagable with said wedge memberand longitudinally moveable in a distal direction to eject said staples;a locking mechanism for preventing distal movement of said firing barafter at least one of said staples has been ejected and said firing barhas been moved proximally a predetermined distance, wherein said wedgemember biases said firing bar into an unlocked position prior to saidstaples being deployed and wherein said wedge member and said firing barare not cooperatively engaged when said instrument is in a lockedposition; and a biasing feature which biases said firing bar in anunlocked position prior to said firing bar engaging said wedge member.2. The surgical device according to claim 1 wherein said biasing featureis attached to said firing bar.
 3. The surgical instrument of claim 1wherein at least one of said wedge member or said firing bar includes acoupling feature, said coupling feature cooperatively engaging saidfiring bar to said wedge member and preventing engagement of said firingbar with said lockout mechanism.
 4. The surgical instrument of claim 3wherein said coupling feature is an extension member cooperativelyengagable with at least one of said wedge member or said firing bar. 5.The surgical instrument of claim 4 including a reception feature on atleast one of said wedge member or said firing bar to cooperativelyreceive said extension member.
 6. The surgical instrument of claim 1further including at least one pin member extending from said firingbar, at least one of said pin members engaging with said lockoutmechanism to lock said firing bar.
 7. The surgical instrument of claims1 further including a spring, said spring normally biasing said firingbar towards said lockout mechanism.
 8. The surgical instrument of claim7 wherein said firing bar includes a sharp edge for cutting tissue. 9.The surgical instrument of claim 1 wherein said firing bar includes asharp edge for cutting tissue.
 10. A surgical stapling instrumentcomprising: an elongate channel extending from said surgical staplinginstrument; a cartridge supported in said elongate channel andcontaining plurality of staples A wedge member, said wedge membermoveable longitudinally within said cartridge to eject said staples fromsaid cartridge; a firing bar cooperatively engagable with said wedgemember and longitudinally moveable in a distal direction to eject saidstaples; and a locking mechanism for locking said firing bar to saidelongate channel by preventing distal movement of said firing bar afterat least one of said staples has been ejected and said firing bar hasbeen moved proximally a predetermined distance, wherein said wedgemember biases said firing bar into an unlocked position prior to saidstaples being deployed and wherein said wedge member and said firing barare not cooperatively engage when said instrument is in a lockedposition; and a biasing feature which operably engages with saidelongate channel to bias said firing bar in an unlocked position priorto said firing bar engaging said wedge member.
 11. The surgical deviceaccording to claim 10 wherein said biasing feature is attached to saidfiring bar.
 12. The surgical stapling instrument of claim 10 whereinsaid elongate channel includes at least one reception feature forlocking engagement with said firing bar.
 13. The surgical staplinginstrument of claim 12 including as least one pin member extending fromsaid firing bar, at least one of said at least one pin members capableof locking engagement with said at least one reception feature of saidelongate channel.
 14. The surgical stapling instrument of claim 10including a spring member for normally biasing said firing bar towardslocking engagement with said elongate channel.
 15. The surgicalinstrument of claim 10 wherein a least one of said wedge member or saidfiring bar includes a coupling feature, said coupling featurecooperatively engaging said firing bar to said wedge member andpreventing engagement of said firing bar with said lockout mechanism.16. The surgical instrument of claim 15 wherein said elongate channelincludes an open channel slot for passage of the firing member therein,said channel slot having a distal end and a proximal end distal to saidbiasing feature, wherein when said biasing feature of said firing barmoves longitudinally a predetermined distance, said biasing featuredistance, said biasing member disengages with said elongate channel. 17.The surgical instrument of claim 15 wherein said coupling feature is anextension member cooperatively engagable with at least one said wedgemember or said firing bar.
 18. The surgical instrument of claim 17including a reception feature on at least one of said wedge member orsaid firing bar to cooperatively receive said extension member.
 19. Thesurgical instrument of claim 10 including a support member on saidfiring bar, said support member interacting with said elongate channelto align said firing member with said wedge member until said firing barcooperatively engages with said wedge member during an initial portionof said longitudinal movement.
 20. A surgical stapling instrumentcomprising: a cartridge containing a plurality of staples and wedgemember, said wedge member moveable longitudinally within said cartridgeto eject said staples from said cartridge; firing bar cooperativelyengagable with said wedge member and longitudinally moveable in distaldirection to eject said staples; and a locking mechanism for preventingdistal movement of said firing bar after at least one said staples hasbeen ejected and said firing bar has been moved proximally apredetermined distance, wherein said wedge member biases said firing barinto an unlocked position prior to said staples being deployed andwherein said wedge member and said firing bar are not cooperativelyengaged when said instrument is in locked position, a firing triggeroperably coupled to said locking mechanism and said firing bar, saidfiring trigger capable of at least one actuation to move said firing bardistally; and a biasing feature which biases said firing bar in anunlocked position prior to said firing bar engaging said wedge member.